Velleman EVM892 - Manual (Page 10)

EVM892
29.04.2010 ©Velleman nv 10
• For DC-current measurements, when a negative polarity is present at the red
test lead, the indicated value is preceded by a “-” sign.
• The mA-range is protected against over-current with an automatic resettable
fuse type 200mA/250V; the 10A range is protected by a ceramic 10A/250V
fuse.
• When measuring currents up to 10A, max. 10s continuous measurement
followed by a 15 minutes break between 2 measurements.
Measuring resistance
Do not perform resistance measurements on live circuits.
• Connect the black test lead to the "COM" jack and the red test lead to the
"VΩHz" jack.
• Select the appropriate "Ω" range with the FUNCTION switch. When the range is
unknown, always select the highest possible range and lower to the appropriate
range.
• Connect the test probes to the circuit/component under test.
• The measured value appears on the display.
Notes:
• Never perform resistance measurements on a live circuit and make sure all
capacitors are completely discharged.
• To increase accuracy when measuring low resistance values, first hold the tips
of the measuring probes together to determine the resistance value of the
test leads. Subtract this value from the measured value of the circuit.
• For resistance measurements above 1MΩ the meter needs a few seconds to
stabilize the read-out.
• Should the measured resistance exceed the selected range or in case of an
open circuit, the display will show “1”.
Testing diodes & continuity
Do not perform continuity or diode measurements on live circuits.
• Connect the black test lead to the "COM" jack and the red test lead to the
"VΩHz" jack.
• Select the 2K range for testing diode or the 200 for continuity tests.
• Connect the test leads to the circuit/component under test.
• Continuity:
When the measured resistance is less than 30Ω a continuous beep is produced
and the resistance is displayed. Should the measured resistance exceed the
selected range or in case of an open circuit, the display will show “1”.
• Diode test:
Connect the red test lead to the anode; connect the black test lead to the
cathode of the diode. The meter will display the approximate forward voltage
drop. If the lead connection is reversed, the meter will display “1”.